Concerned with the ineffectiveness and high costs of incarcerating felony drug offenders, the Kings County District Attorney's Office, located in Brooklyn, New York, designed and implemented a program to divert prison- bound drug offenders to residential, therapeutic community treatment programs. Prosecution is deferred as long as the defendant remains in treatment -- 15 to 24 months. Defendants who successfully complete the program have their charges dismissed, while those who drop out of treatment before program completion are prosecuted on the original charges. The long-term objective of the research is to demonstrate that diversion programs for drug offenders are effective alternatives to incarceration. "Effectiveness" in this context means that diversion is less costly than incarceration and results in lower recidivism rates for participants. To assess effectiveness, the study will use a quasi- experimental design to compare the post-treatment outcomes of program participants (n = 150) with a matched sample of drug offenders (n = 150) who received prison sentences. Subjects will be interviewed at six- and twelve-month intervals after completion of treatment or release from prison. Criminal recidivism, drug use, employment and other measures of social adjustment will be used to assess differences between the two groups. The study will also include a cost-benefit analysis, comparing the costs of the screening and placement of defendants in treatment to the costs of prosecution, conviction and incarceration otherwise incurred. This analysis will also take into account the economic benefits derived from decreased drug use, such as lower crime and victimization costs and increased participation in legitimate economic activities. The third component of the study will examine the unique effects of legal coercion on treatment retention. The Brooklyn District Attorney's program was designed to maximize coercion; defendants face mandatory prison terms if they are convicted after dropping out and there is a special warrant squad specifically assigned to the program to apprehend dropouts swiftly. The coercion variable will be examined in detail using a perception of legal coercion (PLC) scale that the Vera Institute has developed and tested over the past year.